Brisk Wind Advisory 13, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
225 PM AKST Fri Jan 5 2024

.DISCUSSION...

.SYNOPSIS…

Today, we saw a brief break from the widespread active weather,
as the strong low pressure system that impacted much of the area
this week has dissipated. Thus, the pressure gradient has relaxed,
which is allowing winds to trend down quite a bit throughout.
Although, this break in the active weather will be short lived, as
it will return mid-late weekend, as another strong low pressure
system sets it’s sights on the Bering Sea once again. The storm
that has been impacting the area has moved into Bristol Bay and
this continues to decrease in intensity quickly, as it approaches
land. Conditions continue to improve throughout much of the area,
with a few areas still seeing some impacts. Blizzard conditions
remain for those along the Arctic Coast, specifically along/east
of Dead Horse. Through the day today, we will see these conditions
improve from west to east. While gusty winds will remain, the
threat of visibility reductions from blowing snow is decreasing.
Strong winds remain across the West Coast for some, especially
those along the Norton Sound, as well as gusty winds across
Interior summits. Some areas are still seeing light snow,
especially along the Central and Northern Interior, with little to
no accumulation expected from that through the day. As was
mentioned prior, another strong low pressure system is forecast to
move into the Eastern Bering Sea this weekend, bringing strong
winds once again, along with the potential for falling and blowing
snow from the Bering Strait south. We currently have issued
Winter Storm Watches for these areas, with further headline
updates expected as we progress closer to tomorrow.

&&

.DISCUSSION...
Synoptic Analysis and Forecast...

Low pressure system continues to dissipate quickly as it
approaches Bristol Bay. At 500 mb, a 535 dam (decameter) ridge
remains over the Beaufort Sea, starting to shift into a
north/south orientation, with a 510 dam low moving inland over
Bristol Bay. A shortwave trough of low pressure continues to push
through the Bering Strait and away from the forecast area, with a
500 dam low center associated with it. This wave will continue to
elongate and strengthen the strong upper ridge over the Arctic
Ocean, with a north/south orientation by late weekend. A weak
frontal boundary continues to push through the Northern Interior,
resulting in scattered light snow showers.

At the surface, the low over the southern Bering Sea continues to
weaken quicker as it approaches Bristol Bay, now sitting around
977 mb, while the surface high in the Beaufort Sea slow starts to
strengthen, as the shortwave over the Bering Strait enhances it.
Along the Northern Slope, we continue to see the weak surface
trough, which continues to weaken well. Although, it is still
aiding in increasing the surface winds along the Arctic Coast. At
this point the low over Bristol Bay has essentially dissipated,
allowing conditions throughout the forecast area to improve for a
short time. The weather front slowly continues to traverse through
the Northern Interior, which may lead to enhancements in the wind
field along and ahead of it, due to a localized enhancement in
the pressure gradient. Although, with the pressure gradient
rapidly decreasing in intensity, the wind field has also been
subsiding quite a bit. This is allowing for visibility to start
increasing and the blowing snow threat to decrease along the
Northern Slope. Another strong low moves northeast over the north
Pacific and towards the western Aleutians late tonight and into
Saturday, which will be the forecast challenge over the weekend.
Guidance continues to come together with this storm, currently
holding the low pressure center well off of the West Coast, with
impacts mainly on the West Coast, St Lawrence Island, and along
the Arctic Coast once again.

North Slope and Brooks Range…

Blizzard conditions continue to subside this afternoon along the
Arctic coast, east of Utqiagvik. Winds continue to decrease a
little, resulting in a gradual increase in visibility. Low
pressure trough is still situated across the Northern Slope,
decreasing in intensity from the west. Later this weekend, this
pressure trough will restrengthen as the next low approaches,
aiding in increasing the winds. With the easing of the pressure
gradient currently, we are not expecting the winds to be as strong
as they were the previous days, mainly forecasting between 40-50
mph gusts. Winds have decreased east towards Dead Horse this
morning, where visibility has also improved. Thus, we have
canceled the Blizzard Warning for those areas this morning and
issued a Winter Weather Advisory to cover any remaining blowing
snow and low visibility. These improvements will slowly make their
way eastward through this afternoon and evening. Clear to mostly
clear skies will prevail through Saturday. After a brief period of
improved conditions along the Arctic Coast, we will see
conditions deteriorate once again Sunday and through Monday, from
Wainwright to Kaktovik. Very strong winds will return to the area,
bringing another prolonged period of blowing snow. Will need to
continue to monitor the ground blizzard potential and issue
headlines if necessary.

West Coast and Western Interior…

East to northeasterly winds continue to slowly subside along the
West Coast and Western Interior, as the pressure gradient
decreases significantly over the area. Although, we will continue
to see strong easterly winds through the Norton Sound. Granted,
these will be much lower than the previous days, but they remain
gusty at times. Thus, the threat for blowing snow and reduced
visibility decreases substantially for the next 24 hours. The
stretch of quieter weather will be short lived because we will see
another strong low pressure system move into the Bering Sea,
which has the potential to bring gusty winds once again, resulting
in possible blowing snow on Saturday through Monday. Along with
the impacts of blowing snow, we can see falling snow along the YK
Delta, West Coast, and towards St Lawrence Island. Currently, we
are expecting a widespread area of 1-3” of snow through the YK
Delta and parts of the Western Interior, along with the southern
half of the Seward Peninsula. Also, higher snowfall totals can be
seen at the higher elevations, generally from Russian Mission and
north through Kaltag, where we are currently forecasting between
4-8” of snow. Along with the falling snow, gusty winds will
accompany this storm. Thus, blizzard conditions will be possible
at times. Currently, we have a Winter Storm Watch out for these
areas, highlighting the falling/blowing snow, along with the
possible blizzard conditions. We have also opted to issue a High
Wind Watch for Unalakleet, as high winds are forecast and we
overachieved guidance with the last storm. Current guidance
indicates the potential for upwards to 60 mph winds.

Central and Eastern Interior…

The light snow and gusty winds that were seen over the last 24
hours have moved out of the area for the most part, with some
areas still seeing gusty winds, mainly at elevation. The Tanana
Valley Jet remains through the valley, but has drastically
decreased in magnitude, with winds between to 25-35 mph. This will
continue to decrease through tomorrow, before increasing once
again on Sunday. Much of the area will remain dry though this
period, with increases in winds throughout, thanks to down slope
winds generated by the passing storm system over the Bering Sea.
There will be some areas that see light snow from this system, but
that will generally be focused south along the Alaska Range and
west of the Tanana Valley. These areas will generally see a half
inch or less, with upwards to an inch along the northern side of
the Alaska Range. Cloud cover has decreased substantially and we
will remain mostly clear through Saturday, with increasing cloud
cover expected Sunday as the we see moisture increase due to the
passing storm system off the West Coast.

Extended Forecast Days 4-7…

Active weather pattern continues into early next week, as another
strong low moves north out of the northern Pacific and through
the Bering Sea Saturday night into Sunday. As mentioned above,
this low will bring another round of strong winds from the Seward
Peninsula south, as well as falling and blowing snow. This would
leave the largest impacts situated over the West Coast and into St
Lawrence Island, where falling/blowing snow and strong winds
return. This system is expected to impact the area through Monday,
with conditions improving Tuesday and beyond. After this system
passes through, a large ridge is forecast to set up over the
Central Interior, with a barrage of shortwave troughs forecast to
pass through western Alaska and ride along the ridge. This will
bring along several chances for precipitation through next week.

Coastal Hazard Potential Days 3 and 4...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Winter Storm Watch for AKZ821-822.
     Winter Storm Watch for AKZ824-829-830.
     Winter Storm Watch for AKZ825-826.
     Winter Storm Watch for AKZ827.
     Winter Weather Advisory for AKZ804-805.
PK...Gale Warning for PKZ801-802-805>808-850>854.
     Gale Warning for PKZ803-816-817.
     Gale Warning for PKZ804-809-855-856.
     Gale Warning for PKZ810.
     Brisk Wind Advisory for PKZ811.
     Brisk Wind Advisory for PKZ812-813-857>859.
     Gale Warning for PKZ814-860.
     Gale Warning for PKZ815-861.
&&